1. Field of the Invention
This invention relates to a wireless control apparatus wirelessly connected to a wireless communication apparatus, as well as to a system comprising the wireless communication apparatus and the wireless control apparatus.
2. Description of the Related Art
A wireless communication system known in the art comprises a wireless control apparatus (master) and a wireless communication apparatus (slave) wirelessly connected to the wireless control apparatus.
When a transmission request is issued from the slave side or an incoming call is terminated at the slave side in a wireless communication system of this kind, the master searches for and decides upon the communication channel used in this communication between the master and slave and so notifies the slave using a control channel, whereupon the slave is shifted to the communication channel of which it has been notified, thereby establishing a wireless link.
When communication ends, control for the purpose of cutting off the wireless link is carried out over a prescribed period of time, whereupon the wireless link is cut.
However, when an incoming call to the slave is detected after communication ends, the wireless link is cut temporarily. This is despite the fact that the wireless link has not been cut through the link cutting control operation because this operation is still in progress. This means that a new control channel is temporarily occupied to search for and decide upon an idle communication channel and establish a wireless link anew, whereupon communication commences. This procedure takes time. Moreover, if the wireless link cannot be established the second time, it may not be possible to perform communication in response to the incoming call.
Further, in order to make all slaves ring at the time of an incoming call from a communication line in a situation where a plurality of slaves exist, wireless links are established to all of the slaves. If an outgoing call is then abandoned by disconnection on the calling side, the wireless links to the slaves are cut. Or, if a slave responds to the incoming call, the wireless links to slaves other than the responding slave are disconnected.
Accordingly, if a party not sought by the calling side answers the incoming call, it is required that the call be transferred. When the transfer is made, the slave that is the destination of the transfer must re-establish the wireless link and the calling party is made to wait until this is achieved.
In particular, when there is an incoming call from another outside line or an outgoing call to a communication apparatus of another extension in the case of communication apparatus or private branch exchange accommodating a plurality of communication lines (outside lines) and also having a number of extensions, there are instances where a procedure for establishing a wireless link with the other communication apparatus is made to wait while a procedure for establishing a wireless link is being executed for the incoming call or outgoing call. It may take several seconds or more before the communication apparatus that is the destination of the transfer answers or before there is a hold response made by the other communication apparatus. The result is poor operability.